The invention relates to a tool for use in hand power device, i.e., such as percussion drilling devices and comprises two recesses which are closed axially at both sides, located diametrically opposite one another, and cooperate with locking bodies, at least three rotary driving grooves for strip-shaped rotary drivers, which rotary driving grooves are open out at the rear end of the tool shank, are arranged on both sides of a longitudinal plane extending through the two recesses, and are arranged so as to be distributed along the circumference in such a way that two rotary driving grooves are never located diametrically opposite one another in any case.
A tool of the type under consideration is known from DE-P 37 16 915.7. The tool comprises recesses at its shank which are closed at both sides and located diametrically opposite one another, and rotary driving grooves which open out toward the rear end of the tool shank, are provided at both sides of a longitudinal plane extending through these recesses. In order to prevent the tools from being inserted incorrectly, the rotary driving grooves are arranged asymmetrically in such a way that two of them are never located diametrically opposite one another.
While this known tool can fully meet requirements with respect to use, the asymmetrical arrangement of the rotary driving grooves results in an irregular cross-sectional division of the remaining cross-section of the tool shank, particularly as seen from the longitudinal plane extending through the recesses. As a result of this irregular cross-sectional division, production of the rotary driving grooves in particular is only possible by a machining operation, which leads to disadvantages in production chiefly in economical respects. A non-cutting shaping is not possible without subsequent extremely costly aligning processes because of the volume which must be shaped irregularly.